Saturday, February 14, 2009
Renewable power in Jackson, Maine
People are getting upset about energy in Maine again. This is not surprising. In such a cold wintry place, energy is vitally important, and anything that important is always controversial.
The most recent controversy is over wind energy in Jackson, my home town. Which is funny to me since Jackson is really a beautiful almost unbroken, rolling hilly forest, and energy here is abundant.
Our old Maine farmhouse runs primarily on Jackson-made energy from recent sunlight, and far less on fossil fuel (which is really ancient sunlight) from away. As a professor who teaches about energy efficiency and renewable energy, and as a climate policy wonk, this is important to me, and has taken a fair amount of effort with insulation and caulk and spray foam to achieve.
But it does run on sunshine.
Visitors are often confused, however, when they look for the solar panels and wind turbines that most folks seem to expect when confronted with a "green" house. But the fact of the matter is that it isn't quite that hard or expensive to run a house on green power.
The primary source of green power at our house is sunlight. This is collected by 15.5 acres of grass and trees. The grass goes into eight sheep, who use it to make meat and fleece. The meat we eat, in the form of surplus lambs. The fleece, most recently, has gone on to a student's experiment in fleece insulation, of which perhaps more later. But it's really the trees that are the thing.
15.5 acres of fairly rapidly growing trees is about 15 cords, or 1,900 cubic feet, or 54 cubic meters of new wood per year, primarily hardwoods, primarily ash. This is about 20,000 kilograms, or 20 metric tonnes. That much ashwood contains 350 million btus of energy, or about 103 megawatt hours (MWH).
We only use a little more than a third of this production. The rest is sequestered in the growing forest. This helps make up for the fact that our current forest management regime is intended to reduce the smaller trees to make room for grass for animals, leaving larger ones for firewood and cover.
So that would be about 33 MWH total from firewood.
By the way, when I see the bright orange light from our woodstove door, I immediately think of the stored sunlight it represents. This is a comforting thought, especially in the middle of winter.
The next largest supply of energy is from electricity. We purchase our power directly from a company that owns and runs wind turbines, and that aggregates power from Maine hydrodams. There are environmental impacts from both, but the hydrodams have been in place for many years, and are more or less accepted parts of the Maine landscape by now, with their own ecologies and human and wildlife communities, so we opted for hydropower. In the future we may switch all or part to wind, mostly to show support for this new Maine industry which I find valuable, and which is beleaguered by local environmentalists and neighbors. But for right now, our power comes from hydroelectric dams. It gets put into the grid, and the electrons set in motion by the spinning generators at the dam get mixed up with all the other electrons, but we take out as many as are put in and as we paid for, actually less electrons than are made to move for us, taking into account transmission losses, and so we purchase and use moving electrons, or electricity that is made by hydropower, which is also made by the recent sunlight that evaporated the seawater and river and lake and groundwater that became the rain that filled the dam.
So again, we are running on recent sunlight.
Our house uses about 4.8 MWH/year of electricity, mostly for light, entertainment, and refrigeration, but also a little for heat. This is a little less than the national average of about 10 MWH/year.
The house uses about 850 lbs of propane, a fossil fuel, which is about 0.38 of a metric tonne, and contains a further 5.3 MWH of energy. This is very old sunlight, and is used for hot water and cooking.
Finally, because heat energy from wood is less regulated, and requires our presence to feed the woodstoves, we run an oil furnace in the background all of the time in winter. This is also very old sunlight, and its use in our house is strictly controlled; and so it only takes over when the heat from the woodstoves die, or when I decide to nudge up the thermostat to take the chill off more quickly than the woodstoves can. The furnace thermostat is set to 60 degrees F, and so on a cold day it kicks in a few hours after we leave. This uses between 50 and 150 gallons of number two heat oil per year, an average of 100 gallons, a further 4 MWH.
So the total of all this energy is:
Firewood: 33 MWH
Hydropower: 4.8 MWH
Propane: 5.3 MWH
Heat Oil: 4 MWH
Total: 47.1 MWH
Percentage of total household energy consumption that is renewable is 37.8/47.1*100, or 82%.
We could definitely do better than this, but to be reasonable, we also drive two cars, which together consume about 600 gallons or 2,700 liters of gasoline, which is another 25 MWH, quite a lot more energy. Since we can save some of this energy simply by only driving one car whenever we can, which also saves quite a bit of money, we would be financially better off right now not by trying to save more household fossil energy consumption, but by trying to carpool more often. These last few weeks of the spring semester we have been able to carpool an average of 60-70% of the time, which compares well to last semester's 30-40% of the time. Of course, our ability to carpool is directly related to the timing of the teaching and meeting schedule that Unity College gives us. If our schedules are at normal 8-4 working hours, then we can carpool. If not, if one of us has an early or late meeting, the other must either leave late or come home early to feed the animals and the woodstove.
The extent that we are able to carpool, and the amount of time that our cars last, is also directly related to our ability to save money to buy new energy-saving appliances and equipment for the house, or to buy a more efficient car.
This is all a pretty carefully constructed system of rational trade-offs, I guess. But it works for us and we are able to progress towards less overall fossil energy use per year. We are reaching the limits of what can be achieved cheaply with insulation and caulking and firewood. The next stages -- an electric or plug-in hybrid car, a new solar thermal hot water system, possibly combined with an electric on-demand hot water heater for when the sun doesn't shine, these are all relatively expensive.
But even then, the heart of the system will be the 15.5 acres of woodland, whose green leaves we hope to see spread soon this spring to catch some more of that sunshine for us.
Just recently, a group of our neighbors from Jackson, Maine published a newsletter and web page opposing the wind power developments proposed for the Mt. Harris ridgeline to the north. I probably know that land as well if not better than anyone, since I explore it extensively each fall while teaching map reading to the trainee park rangers and game wardens of Unity College, or on my own or with Aimee on Sunday walks.
It is a very beautiful area, the scenic jewel of the Great Forest of Jackson and Dixmont.
There may be quite a lot of very large wind turbines on that hilltop soon. Our neighbors are really anxious, and many do not wish to see the turbines go ahead. They are asking a lot of very awkward questions at Town Meetings and in their paper and web site.
For my part, I think the company, which is the same one I get my hydropower from, should perhaps think about a few less turbines. While my neighbors might think about accepting a few, or even getting one or more that are owned by the community.
As for my neighbors, I wonder if we sat down together and added up all our energy consumption and studied all the difficulties and problems that are caused by each and every kind of energy, well, I wonder if we might not then realize that the turbines are possibly a better investment than patrolling the Persian Gulf, or building new nuclear power plants, or waiting for climate change to revise the entire north-eastern forest ecosystem.
The problem is, I think, a) we don't do that. Instead we shout at Town Meetings. And then b) even the country as a whole doesn't do that, which is why a power company I otherwise support can get away with turning this part of Maine into an energy exporter for other parts of the country, essentially an energy colony. And then c) I'm a very boring, very rational old college professor who just wants his students to grow up fast, and put away childish things like yelling at each other, and think about it as well as they can.
Believe me, I understand the limitations of my wishes very, very, ruefully well.
I don't believe in black and white when it comes to energy. Even my firewood pile, which is probably one of the cleanest forms of energy, still produces solid waste in the form of ash, air pollution in the form of particulate, and environmental damage each time I cut down a tree and cut it up for firewood.
A few wind turbines on Jackson ridge would probably be a good thing. They might help us all learn to run as much as we can on recent sunlight here in Jackson. I for one would like to use this energy. It would be better if the community could get the most benefit out of them, particularly if we owned one or more of them, and it would be better if there were less of them than are proposed.
The community probably has it in its power to require some or all of this, but it would take a good lawyer to figure it out. To begin, we might start by doing our energy sums.